In a typical air cooled condenser of a fuel, coal or gas-fired power station, steam flows into cooling tube arrays or bundles, which are cooled by a forced air flow. Two arrays, which each form a generally flat, rectangular field, are erected to form an A-shaped structure. The cooling tubes are fin tubes, i.e. tubes having cooling fins integrally mounted or formed thereon. The steam enters the cooling tubes in parallel flow from the top. Fans that are arranged below the structure draw ambient air and discharge it along the cooling tubes for cooling. The air crosses the tube arrays from below.
Because of the outdoor installation, and because the fans draw ambient air, dirt gradually accumulates on the cooling tube arrays. Resulting cooling performance deficits may involve performance deficits of the power station, so that cleaning is required. However, cleaning large cooling tube arrays manually using high-pressure cleaners is dangerous and hard labor. For example, ambient temperatures at the working area may even reach e.g. 60° C. to 70° C. A cooling tube array may have a height along the inclined direction of the tubes of e.g. 10 meters, and may extend over a length of e.g. 80 meters in the lateral direction. The inclination angle may be 60° or more with respect to the horizontal.
WO 2013/178353 A2 describes a cleaning apparatus for spraying cooling coils with water. The apparatus has travelling profiles that can be displaced over the cooling coils, and a carrying system for nozzles can be displaced on the travelling profiles. The nozzle-carrying system is arranged above the travelling profiles and carries separate rows of nozzles on both sides of the carrying system, so that the travelling profiles may be supported from below while permitting the nozzle-carrying system to travel onto a portion of the travelling profiles that extends beyond the support, without interfering with the support. In one example, a triangular truss beam has three chord tubes, and the nozzle-carrying system is carried on the top chord tubes by respective pairs of rollers that are displaced in the circumferential direction of the respective chord tube on which they travel. The single lower chord tube is mounted on a column of a support of upside down T-shape that may be passed by the nozzle-carrying system. Thereby, a cleaning width of the rows of nozzles may be increased as compared to a cleaning width of a conventional cleaning apparatus, in which the nozzle-carrying system is arranged below a travelling profile and is dimensioned in order to be able to pass through a support portal that supports the travelling profile. Further examples also describe a square truss beam. In one example, pairs of rollers travel on two bottom chord tubes of the truss beam. In another example, pairs of rollers travel on two top chord tubes of the truss beam.
DE 10 2012 021 177 A1 and DE 10 2012 021 178 A1 describe similar cleaning devices.
EP 1604164 B1 and DE 10 2009 052 676 A1 describe a mobile cleaning device for air cooled condensation units, in which a cleaning nozzle carrier is displaceable suspended from a square profile that is arranged such that a diagonal of the square is vertical. The carrier comprises rollers that travel on the flat sides of the square profile.
EP 2 317 274 A2 and DE 20 2010 017 403 U1 describe cleaning devices for a heat exchanger, with a ladder consisting of side walls and ladder rungs, to which two parallel arranged profiles are fastened, in or on which a nozzle holder is movable. The ladder is mounted on a cooling roof of the heat exchanger. Water is supplied via a tube that is arranged to form a bend, which is laid flat onto a supporting surface of the ladder arrangement of the cleaning device, which surface is parallel to the plane of the cooling roof. Forming the bend allows the tube to follow the movement of the nozzle holder up and down along the ladder.
EP 2 317 273 A2 and DE 10 2010 010 011 A1 describe similar cleaning devices, wherein the water supply tube is arranged in an energy chain, which guides the tube and limits a bending angle of the tube and protects the tube.